Current-modifier.



0. M. LEICH.

CURRENT MODIFIER.

APPLICATION FILED MAY 18,1916.

Patented July 9, 1918.

77,237 @lmh UNITED STATES PATENT OFFICE.

osoen m. LEIGH, or canoe, rumors, ASSIGNOR r0 LEIGH ELECTRIC COMPANY, or

GENOA, rumors.

CUBRENT-MODIFIER.

Original application filed. March 24,1915, Serial No. 16,564. Dividedand this application filed May 18, 1916.

Specification of tetters Patent.

Patented July 9, 1918.

Serial No. 98,266.

To all whom it may concern Be it known that I, OSCAR M. LEIGH, a citizenof the United States, residing at Genoa, in the county of Dekalb andState of Illinois, have invented a certain new and useful Improvement inCurrent-Modifiers, of which the following is a full, clear, con cise,and exact description, reference being had to the accompanying drawings,forming a part of this specification.

My invention relates to current modifiers, and in one form of itsapplication is of particular use in providing a vibrator for instancewhich can be operated directly from an alternating current circuit andprovide intermittentor pulsatory current of a frequency other than thatof the source. More specifically, my invention finds great applicationin connection with vibrators used for signaling purposes in telephoneexchanges or similar places, and my invention will be readily understoodif in the description which I will now give I will explain it moreparticularly as applied to such a telephone, vibrator. V

My application herein is a divisional a plication of my priorapplication Serial 0. 16,564, filed March 24, 1915.

en my invention is thus applied, I may saythat in one specific case Ioperate the device from a sixty cycle alternating current whichoperatesa vibrating element. Current from the. source may then be ledthrough a suitable rectifier if it is desired to rectify the current,and this rectified current will then be reimpressed on the ringingcircuit through the interposition of switchingor similar elementscontrolled by the vibratin element aforesaid.

I m explain my invention more in detail as applied to two specificstyles of rectifiers by referring to the accompanying drawings, inwhich- Figure 1 diagrammatically sets forth my invention in connectionwith an electrolytic rectifier, and

Fig. 2 is a similar View with an electromagnetic rectifier.

Referring to Fig. 1,1 have a source of alternating current 1 whichpreferably is of the sixty cycle, one hundred and ten volt type assupplying current to the conductors 2 and 3. I show a ringing circuithaving the conductors 4 and o whlch when my invention is used fortelephone purposes lead directly to the switch board, where through theinterposition of ringing keys these conductors 4 and 5 are connectedwith the telephone line to call the substation signal as is customary. Imight say here that my improved device can supply the current at anydesired frequency so that it may not only be used for operating-theordinary polarized bells of telephone receivers, but may also operateharmonic ringers or similar devices as may be required. One greatadvantage in the use of my.vi brator as will appear presently resides inthe fact that the vibrator requires'a practically negligible no-loadcurrent so that the expense of operation is reduced to a minimum. I showa rectifier 6 which may be of any desired type of rectifier, but whichherein is of the electrolytic type having the jar 7 the lead electrode 8and the two platinum electrodes 9 and 10. It is well known of coursethat with the platinum electrodein the electrolytic cell current of onedirection only passes therethrough. The rectifier is used in connectionwith two impedance coils 11 and 12 which are directly or inductivelconnected across the conductors 2 and 3, the circuit being traceablefrom the conductor 2 by way of the conductor 13, impedance coil 11,impedance coil 12, conductor 14, to the line conductor 3.

I have provided a vibrating element- 15 consisting of a spring which maybe tuned to a certain frequency if desired so that if actuated electromagnetically it will vibrate with said frequency. A permanent mounting16 is provided for this spring. This spring carries a contact element 17which in conjunction with the stationary back contact 18 controls thecircuit through coils l9 and 20 forming the energizing coils of anelectromagnet 21. The circuit through the coils l9 and 20 may then betraced from the line conductor 3 by way of conductor 22, coils l9 and 20in parallel, by way of conductor 23 to the spring 15, the spring contact17, the back contact 18, and b way of conductorsQl and 13 to the lineconductor 2. It will thus be seen that the current from the source isused directly to actuate the vibratingclement 15. This vibrating elemeat15 carries a weight 95 if desired further toadj'ust its frequency ofvibration,

The coils 19 and 20 are each preferably of high resistance, forinstance, one thousand ohms each so that very little no-load current isrequired to actuate the spring 15. The spring 15 carries an ironarmature 26 which cooperates with the cores of the coils 19 and 20. Theelectromagnet 21 in addition to the keeper 27 is provided with a thirdleg 28 so that the armature 26 is more or less uninfluenced by thealternations of the current from the alternating current source, thespring 15 and the energization of the coils 19 and 20 being controlledby the cooperation between the elements 17 and 18 as in the ordinaryvibrating bell. One of the coils, the coil 19, for instance, has acondenser 29 included serially therewith so as to throw the currents inthe coils 19 and 20 out of phase so that there is never a dead pointint-the en'ergization, and the third leg 28 assists further incooperating toward this end. The armature 26thl1s is actuated'by thecoils 19 and'20 as the circuit through said coils is controlled by theelements 17 and 18 irrespective of the alternating character of thecurrent threading said coils. The vibrator 15- carriescircuitcontrolling springs 30 and 31 which cooperate with back contacts32 and 33. The springs 30 and 31 are insulated from the vibrator 15, areelectrically connected together; however, and connected by means of theconductor 34 with "the intermediate junction point 35 of the impedancecoils l1 and 12. ,The impedance coils 11 and 12 of courseare ofsuilicient impedance that their no-load requirements are very small. Theplatinum electrode 10 is'directly connected by means of the conductor 35with the conductor 14 leading to the line conductor 3. The platinumelectrode 9 is intermittently connected with the other line conductor 2in accordance with the operations of a rela .36, this circuit beingtraceable from sald electrode 9 by way of conductor 37, contact spring38, front contact 39, conductor 40, to the conductor 13 which leadsdirectly to the line conductor 2.

Thus. whenever the relay 36 is energized the electrolytic cell isdirectly :in bridgeof the mains 2 and 3. I provide a transformer 41consisting of the primary windings 42 and 43 and the secondarywinding44. The coils 42 and 43 are connected in parallel except that-they aredifferentially connected as shown"'with a free terminal of each lead-1ngrespectively to the front contacts 32 and 33. The'remaining terminalsof these primary coils 42 and 43 are connected together and thenconnected by means of the con-. ductor 45 to the lead electrode 8. Thesecondary winding 44 has one terminal directly connected to the ringinglead 5 and its other terminal is connected to the armature 46 of therate of vibration depending upon the relay 36. The armature .46coiiperates with a front contact 47. .This relay 36 has two coilsrespectively 48 and 49, the coil 48 being low wound, say fifty ohms, andthe coil 49 being high wound, say one thousand ohms.

interposition merely of the fifty ohm coil 48- whose magnetism howeveris sufiicient to hold the armature 46 so long as the circuit across theleads 4 and 5 remains closed. 1 may say that the transformer 41 servesto change the voltage as may be required and T find in one form of thedevice that I have satisfactory service if the coils 42 and 43 each haveeight hundred turns, whereas the winding 44 has twelve hundred turns.

1 may say also-that the solution which I use in the electrolytic, cellmay preferably be ammoniumphosphate. I -may say also that in thecontinuous operation'of the electrolytic cell 6 sediment forms whichcollects at the bottom and which must be periodically removed. In orderto reduce the amount of sediment thus thrown down, the circuit throughthe electrolytic cell is normally maintained open by the elements 38 and39 of the relay 6. The no-load current to operate this device would bethat consumed by the electromagnet 21 and that flowing through the'coils11 and 12. This noload currentis less than four-hundredths of an ampere.Of course, when thedevice is operating and has the electrolytic cell inbridge of the mains 2 and 3 then there is a slight additional leakagewhich however is similarly small.

Now in the operation of the device, let it be assumed that the vibratoris operating as ex lained. It is to be remembered that the coils 42 and43 are connected to the lead electrode 8 and respectively to thecontacts 32 and 33. Thus as the vibrator moves to and fro one coil 42and then the other coil 43 is connected between the'lead electrode 8 andthe junction point 35 between the im pedances 11, and 12. There isthusapulsatory rectified current passing through the coils 42 and 43. everare difierently wound and thus their effects are of opposite sign-on thewinding 44 even though these coils receive their current at times fromthe platinum electrode 9 and at other times from the platinum electrode10.

It must be remembered of course that the The coils 42 and 43 how- 1 Ivibrator 15 vibrates in accordance with its predetermined frequency orrateof vibration entirely unafl'ected as to whether the break at theelements 17 and 18 occurs at the peak of the wave or atany other time,this vibrator not necessarily operating in synchronism with the cyclesof current furnished by the source 1.

Assume however that the elements 31 and 33 are in contact throughout thecourse of two or three cycles of alternating current, at that time thecoil 43 is in circuit and receives several impulses all in the samedirection however, alternately from the platinum electrode 9 and theplatinum electrode 10. There is thus a unidirectional pulsating currenttraversing the coil 43 of a given sign. The next instant when theelements 42, but on account of its reverse connection the magneticeffect is opposite to that of the coil 43 so that a current of oppositesign flows through the winding 44. Thus for instance if it were desiredto transform the sixty cycle current of the source into a twenty cycleringing current, then the vibrator 15 would be tuned to cause atransference of current from one coil 42 to the other coil 43 and viceversa, once during each three cycles so that coil 42 for instance wouldreceive three pulsations of similar sign, and then coil 43 would receivethree pulsations of similar sign whose magnetic efiects'however would beof opposite sign.

Referring now to Fig. 2, I have shown my invention as used in connectionwith an electromagnet rectifier 50 having the operating coils 51 and 52which control a polarized armature 53. The armature '53- cooperates withcontact elements 54 and 55 to send a rectified current by way of theconductor 45 'through the rimary coils 42 and 43 respectively. A poarized magnet 56 is indicated. Similarly to the arrangement of Fig. 1the rectified. current in the winding 42 produces the opposite kind of afield to i thought the nature of my that produced in the coil 43 byreason of the reverse connection of these coils as is clear. Thearmature 53 of course vibrates with the frequency of the alternatingcurrent and thus the impulses of alternating current are rectified so asto establish a rectified current by way, of the conductor 45. Theoperation is similar to that shown in'Fig. 1.

From What has been described it is invention will be readily clear to.those skilled in the art and it will also be clear that manymodifications may be made within the scope of the appended claimswithout departing from a fundamental rate of pulsation different fromthe rate of pulsation of said rectified current.

2. In a selective fre uency signaling system the combination 0 .analternate current source of supply, a signalingcircuit, a vibratoryrectifier for changing the alternating current to a pulsatoryuni-directional current, and a vibratory electromagnetically operatedmeans excited from the alternating current source. of supply connectedto feed said rectified-current to said signaling circuit at afundamental rate of pulsation different from the rate of pulsatlon ofsaid rectified current.

3. In a selective frequency signaling system the combination of analternate current source of supply, a signaling circuit, a vibratoryrectifier for changing the alternating current to a pulsatoryuni-directional current, a vibratory electro-magnetically operated meansconnected to feed said rectified current to said signaling circuit at afundamental rate of pulsation different from the rate of pulsation ofsaid rectified current, and a transformer interposed between saidvibratory means and-said signaling circuit.

4. In a selective frepuency signaling sys- I an alternate current" temthe combination 0 source of supply, a signaling circuit, 9. vibratoryrectifier for changing the alternating current to a pulsatoryuni-directional current, a vibratory electromagnetically. op,-

erated means excited from the alternating current source of supplyconnected to feed said rectified current to said'signaling circuit at afundamental rate of pulsation clifferent from the rate'of pulsation ofsaid rectified current, and a transformer inters posed between saidvibratory means and said signaling circuit.

In witness whereof, I hereunto subscribe my name this 25th day .ofApril, A. D. 1916.

OSCAR M. LEIGH.

